Choral et Variations Op.37 is a short piece for trumpet and piano written by Marc Delmas, and used by students at the Paris Conservatory in the early 20th century. The variations of this piece are divided into fully separate movements.
The highest note in the piece is a concert Bb above the staff and the lowest is concert G below the staff. There are rhythmically intricate sections, including triplet 32nd notes, but they are written in ergonomic fashion.
Take a look at the samples to the left, and then click above for a single PDF download of the solo part and score.